Open VSX Registry Supply-Chain Attack Spreads GlassWorm via Compromised VSCode Extensions
A supply-chain compromise of the Open VSX Registry led to malicious updates being pushed to legitimate Visual Studio Code extensions after attackers gained access to a developer’s publishing credentials (likely via a leaked token or other unauthorized access). Reporting indicates four established extensions from the oorzc publisher were trojanized and distributed via Open VSX before being removed, with prior legitimate adoption measured in the tens of thousands of downloads and subsequent exposure affecting downstream developer environments.
The injected payload delivered the GlassWorm malware/loader, which executes via obfuscated JavaScript embedded in the extension and includes environment checks (notably avoiding execution on Russian-locale systems). Technical details describe a multi-stage loader with capabilities aligned to credential and data theft, including macOS credential and cryptocurrency wallet targeting, and use of techniques such as EtherHiding to retrieve command-and-control infrastructure dynamically; defenders are advised to identify and remove affected extension versions and review developer endpoints for signs of compromise and credential/token leakage.
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How this story unfolded
4 events from the most recent confirmed update back to the earliest known activity.
Open VSX confirmed unauthorized publishing access and removed releases
After notification from Socket, the Eclipse Foundation/Open VSX confirmed unauthorized access to the publisher's publishing resources. The registry revoked the publisher's tokens and removed the malicious releases, with one extension reportedly removed entirely because it had multiple malicious releases.
Socket disclosed the Open VSX supply-chain attack
Researchers at Socket reported that the malicious Open VSX updates delivered the GlassWorm malware loader via a compromised developer account rather than fake packages. Their analysis linked the campaign to macOS-focused credential and crypto theft, runtime decryption, and command-and-control retrieval via Solana transaction memos.
Four long-standing Open VSX extensions were trojanized
On January 30, 2026, attackers used unauthorized access to the trusted publisher account "oorzc" to publish malicious updates to four previously legitimate Open VSX extensions. The extensions had been benign for about two years and had accumulated more than 22,000 downloads before the malicious releases.
GlassWorm activity first observed in developer ecosystems
GlassWorm activity was first observed in late October 2025, with reporting later describing it as an ongoing campaign affecting developer environments and spreading through malicious extensions. Earlier waves were associated with typosquatting and brandjacking before the Open VSX incident.
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Vulnerabilities, threat actors, malware, products, organizations, and breaches Mallory has linked to this story.
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Open VSX Hijacked: "GlassWorm" Malware Poisons VS Code Extensions
securityonline.info
Open sourceGlassWorm malware campaign expands to Open VSX, targeting macOS users | SC Media
scworld.com
Open sourceGlassWorm Infiltrated VSX Extensions with More than 22,000 Downloads to Attack Developers
cybersecuritynews.com
Open sourceGlassWorm Malware Returns to Shatter Developer Ecosystems
darkreading.com
Open sourceNew GlassWorm attack targets macOS via compromised OpenVSX extensions
bleepingcomputer.com
Open sourceGlassWorm malware targets Open VSX Registry in supply chain attack | SC Media
scworld.com
Open sourceGlassWorm Supply Chain Attack Exploits Open VSX Registry to Infect VSCode Extensions with Advanced Malware
rescana.com
Open sourceOpen VSX Supply Chain Attack Used Compromised Dev Account to Spread GlassWorm
thehackernews.com
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Open VSX Token Exposure and GlassWorm Supply Chain Attack
Eclipse Foundation revoked a small number of leaked access tokens for the Open VSX extension marketplace after a report from Wiz revealed that several Visual Studio Code extensions had inadvertently exposed their tokens in public repositories. This exposure could have allowed attackers to take control of extensions and distribute malware, posing a significant supply chain risk. The foundation confirmed that the leaks were due to developer mistakes, not a compromise of Open VSX infrastructure, and has since implemented new security measures, including a token prefix format and reduced token lifetimes. Additionally, extensions flagged as part of the "GlassWorm" campaign by Koi Security were removed, and the foundation clarified that the reported download numbers were likely inflated by bots and threat actor tactics. The GlassWorm campaign involved the use of hidden malicious code injected with invisible Unicode Private Use Area (PUA) characters, a technique previously observed in npm packages and now seen in compromised Open VSX extensions. Security researchers noted that the same threat actor has shifted focus to GitHub repositories, using increasingly stealthy methods to inject malware into legitimate-looking commits. The campaign highlights the evolving tactics of supply chain attackers and the importance of proactive security measures in open-source ecosystems.
Mar 21, 2026
GlassWorm Supply Chain Attack via Malicious VS Code and Open VSX Extensions
The GlassWorm malware campaign has resurfaced with a third wave of attacks, distributing 24 malicious extensions across the Microsoft Visual Studio Marketplace and Open VSX repositories. These extensions impersonate popular developer tools and frameworks such as Flutter, React, Tailwind, Vim, and Vue, aiming to compromise developer environments. Once installed, the malware attempts to steal credentials for GitHub, npm, and OpenVSX accounts, as well as cryptocurrency wallet data, and can turn infected machines into attacker-controlled nodes for further criminal activity. The attackers have also been observed artificially inflating download counts to increase the visibility and perceived trustworthiness of their malicious extensions. GlassWorm employs advanced evasion techniques, including the use of invisible Unicode characters to hide malicious code and the deployment of a SOCKS proxy and HVNC client for stealthy remote access. Despite previous efforts by Microsoft and Open VSX to remove infected packages and rotate compromised access tokens, the threat actors have continued to return with new publisher accounts and updated extensions. The campaign highlights the ongoing risks in the software supply chain, particularly for developers relying on third-party extensions from public repositories.
Apr 29, 2026
GlassWorm Supply Chain Attack on Visual Studio Code Extensions
A sophisticated supply chain attack has targeted Visual Studio Code (VS Code) extensions, leveraging a self-propagating worm known as GlassWorm. Security researchers at Koi Security discovered the malware after identifying suspicious behavior in an extension called CodeJoy on the OpenVSX marketplace. The worm employs a novel technique using invisible Unicode characters, making the malicious code undetectable to the human eye within code editors. This approach allows the malware to evade traditional detection methods and remain stealthy within compromised extensions. GlassWorm utilizes the Solana blockchain as its primary command-and-control (C2) channel, with Google Calendar serving as a backup C2 infrastructure, enhancing its resilience and making takedown efforts more challenging. The worm has already infected nearly 36,000 developer machines, indicating a significant impact on the developer ecosystem. Once installed, GlassWorm harvests credentials from NPM, GitHub, and Git, enabling it to propagate further by compromising additional packages and extensions. The malware also targets cryptocurrency wallets, seeking to steal digital assets from affected users. Infected systems are converted into SOCKS proxy servers, effectively turning developer machines into part of the attacker's extended C2 infrastructure. Additionally, GlassWorm installs hidden virtual network computing (VNC) servers, granting attackers full remote access to compromised machines. The attack highlights the growing risks associated with open-source marketplaces and the potential for widespread compromise through popular development tools. Security experts emphasize the importance of scrutinizing extension code and implementing stronger guardrails in extension marketplaces to prevent similar attacks. The use of invisible Unicode and blockchain-based C2 channels represents a significant evolution in malware stealth and persistence. The incident underscores the need for developers and organizations to monitor for unusual extension behavior and to regularly audit installed extensions for signs of compromise. The attack also demonstrates the potential for supply chain threats to rapidly scale, given the interconnected nature of developer tools and platforms. As the investigation continues, security vendors and marketplace operators are working to identify and remove malicious extensions and to strengthen defenses against future supply chain attacks.
Apr 25, 2026